This invention relates generally to products useful for home laundering, and more particularly to adjustable strength bleaching compositions, highly advantageous packaging of such compositions, and a method of bleaching involving the combination of the two. More specifically, the invention concerns a highly practical and saleable laundry aid which can be used both on sensitive fabrics/dyes as an all-fabric safe oxygen bleach, and on less vulnerable fabrics/dyes as a much more effective hypohalite bleach of potency similar to that of liquid chlorine bleach.
Typical laundry wash temperatures in the United States continue to decline for various reasons; and with them, the bleaching ability of the oxygen bleaching agents in conventional all-fabric safe bleaches (e.g. sodium perborate). Such agents remain in wide use despite this fact, because of their efficacy at elevated temperatures, and their virtual inability to harm sensitive fabrics and dyes, regardless of the washing conditions. Chlorine bleaches on the other hand, though very potent even at low temperature, are well known to affect adversely many colored fabrics, and they often substantially reduce the efficacy of many fluorescent whitener agents contained in most detergent products.
The ability of peroxymonosulfate to oxidize halides to hypohalites and hypohalous acids; and to consequently boost the overall bleaching effectiveness, is well know in the industry. See U.S. Pat. No. 3,458,446,; French Pat. No. 1,568,919; German Pat. No. 1,269,992, and U.S. Pat. No. 1,162,754. There is also substantial prior art concerning methods of reducing fabric degradation when using a sodium bromide activated bleach. German Pat. No. 2,525,878 (see also U.S. Pat. No. 4,116,878) issued to Fritz Deutscher in January of 1976 teaches that textile degradation can be minimized by adding urea or acetamide to a sodium bromide activated peroxymonosulfate bleach. U.S. Pat. No. 4,123,376 issued to Frederick W. Gray in October of 1978 teaches that certain (other) N-hydrogen compounds inhibit destruction of dyes and overbleaching of dyed materials when used in a sodium bromide promoted peroxymonosulfate bleach composition. U.S. Pat. No. 4,028,263 issued to Frederick Gray in June of 1977 discloses certain fluorescent whitening agents which are relatively stable in such a system for use in a detergent/bleach composition. Each of these patents refers only to bleaching enhancement from bromide ion addition, with no mention of the synergism and possible toxicity conditions which result from using a combination of chloride and bromide salts.